scholarly journals Telmisartan Protects Auditory Hair Cells from Gentamicin-Induced Toxicity in vitro

2020 ◽  
Vol 25 (6) ◽  
pp. 297-308
Author(s):  
Maurizio Cortada ◽  
Eric Wei ◽  
Neha Jain ◽  
Soledad Levano ◽  
Daniel Bodmer
Keyword(s):  
Hair Cells ◽  
Cell Types ◽  
Protective Role ◽  
Angiotensin Ii Receptor Blocker ◽  
Peroxisome Proliferator ◽  
Angiotensin Ii Receptor ◽  
Peroxisome Proliferator Activated Receptor ◽  
Auditory Hair Cells ◽  
Ppar Γ

<b><i>Background:</i></b> Telmisartan is an angiotensin II receptor blocker that has pleiotropic effects and protective properties in different cell types. Moreover, telmisartan has also shown partial agonism on the peroxisome proliferator-activated receptor γ (PPAR-γ). Auditory hair cells (HCs) express PPAR-γ, and the protective role of PPAR-γ agonists on HCs has been shown. <b><i>Objectives:</i></b> The objective of this study was to investigate the effects of telmisartan on gentamicin-induced ototoxicity in vitro. <b><i>Methods:</i></b> Cochlear explants were exposed to gentamicin with or without telmisartan, and/or GW9662, an irreversible PPAR-γ antagonist. <b><i>Results:</i></b> Telmisartan protected auditory HCs against gentamicin-induced ototoxicity. GW9662 completely blocked this protective effect, suggesting that it was mediated by PPAR-γ signaling. Exposure to GW9662 or telmisartan alone was not toxic to auditory HCs. <b><i>Conclusions:</i></b> We found that telmisartan, via PPAR-γ signaling, protects auditory HCs from gentamicin-induced ototoxicity. Therefore, telmisartan could potentially be used in the future to prevent or treat sensorineural hearing loss.

scholarly journals Telmisartan-induced eNOS gene expression is partially independent of its PPAR-gamma agonist property

2012 ◽  
Vol 35 (2) ◽  
pp. 55 ◽  
Author(s):  
Nisa Buset Ríos ◽  
Francisco Rodríguez Esparragón ◽  
José C Rodríguez Pérez
Keyword(s):  
Gene Expression ◽  
Protein Level ◽  
Ppar Gamma ◽  
Enos Gene ◽  
Angiotensin Ii Receptor Blocker ◽  
Peroxisome Proliferator ◽  
Angiotensin Ii Receptor ◽  
Peroxisome Proliferator Activated Receptor ◽  
Enos Activity ◽  
Ppar Γ

Purpose: Telmisartan, an angiotensin II receptor blocker (ARB), also acts as an activator of peroxisome proliferator-activated receptor-gamma (PPAR-gamma; PPAR-γ). Several studies have explored the PPAR-γ-endothelial nitric oxide synthase (eNOS) pathway associated with improvement of endothelial function by telmisartan. The ability of telmisartan to induce gene expression and protein level of eNOS and PPARγ in adipocytes was investigated. Methods: Expression of aP2, PPARγ, eNOS and iNOS genes were measured using the quantitative real-time polymerase chain reaction. The changes, at the protein level, were explored by Western blot, which evaluated the native and phosphorylated eNOS forms, eNOS-Ser1177 and eNOS-Thr495. Results: Adipocytes, exposed to telmisartan, exhibited an increase in PPARγ gene expression but a decrease in protein level. Nonetheless, after the exposure to telmisartan, eNOS-Ser1177 phosphorylation, associated with eNOS activity increment, reached its highest value while eNOS-Thr495 phosphorylation, involved in the inhibition of eNOS activity, showed its lowest value. Conclusion: The results suggest that telmisartan preserves eNOS activity via a mechanism that is partially independent of the PPARγ-eNOS pathway in adipocytes.

scholarly journals Telmisartan Loaded Nanofibers Enhance Re-Endothelialization and Inhibit Neointimal Hyperplasia

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1756
Author(s):  
Chen-Hung Lee ◽  
Kuo-Sheng Liu ◽  
Julien George Roth ◽  
Kuo-Chun Hung ◽  
Yen-Wei Liu ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Neointimal Hyperplasia ◽  
Metal Stents ◽  
Angiotensin Ii Receptor Blocker ◽  
Peroxisome Proliferator ◽  
Angiotensin Ii Receptor ◽  
Biodegradable Stent ◽  
Peroxisome Proliferator Activated Receptor ◽  
Increased Risk

Stent implantation impairs local endothelial function and may be associated with subsequent adverse cardiovascular events. Telmisartan, an angiotensin II receptor blocker that has unique peroxisome proliferator-activated-receptor-gamma-mediated effects on cardiovascular disease, has been shown to enhance endothelial function and limit neointimal hyperplasia. This study utilized hybrid biodegradable/stent nanofibers to facilitate sustained and local delivery of telmisartan to injured arterial vessels. Telmisartan and poly(d,l)-lactide-co-glycolide (PLGA) (75:25) were dissolved in hexafluoroisopropyl alcohol and electrospun into biodegradable nanofibrous tubes which were coated onto metal stents. By releasing 20% of the loaded telmisartan in 30 days, these hybrid biodegradable/stent telmisartan-loaded nanofibers increased the migration of endothelial progenitor cells in vitro, promoted endothelialization, and reduced intimal hyperplasia. As such, this work provides insights into the use of PLGA nanofibers for treating patients with an increased risk of stent restenosis.

scholarly journals Apple Flavonols Mitigate Adipocyte Inflammation and Promote Angiogenic Factors in LPS- and Cobalt Chloride-Stimulated Adipocytes, in Part by a Peroxisome Proliferator-Activated Receptor-γ-Dependent Mechanism

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1386 ◽  
Author(s):  
Danyelle M. Liddle ◽  
Meaghan E. Kavanagh ◽  
Amanda J. Wright ◽  
Lindsay E. Robinson
Keyword(s):  
Mrna Expression ◽  
Cobalt Chloride ◽  
Nuclear Factor Κb ◽  
Diglycidyl Ether ◽  
Low Grade ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Anti Inflammatory

Adipose tissue (AT) expansion induces local hypoxia, a key contributor to the chronic low-grade inflammation that drives obesity-associated disease. Apple flavonols phloretin (PT) and phlorizin (PZ) are suggested anti-inflammatory molecules but their effectiveness in obese AT is inadequately understood. Using in vitro models designed to reproduce the obese AT microenvironment, 3T3-L1 adipocytes were cultured for 24 h with PT or PZ (100 μM) concurrent with the inflammatory stimulus lipopolysaccharide (LPS; 10 ng/mL) and/or the hypoxia mimetic cobalt chloride (CoCl2; 100 μM). Within each condition, PT was more potent than PZ and its effects were partially mediated by peroxisome proliferator-activated receptor (PPAR)-γ (p < 0.05), as tested using the PPAR-γ antagonist bisphenol A diglycidyl ether (BADGE). In LPS-, CoCl2-, or LPS + CoCl2-stimulated adipocytes, PT reduced mRNA expression and/or secreted protein levels of inflammatory and macrophage chemotactic adipokines, and increased that of anti-inflammatory and angiogenic adipokines, which was consistent with reduced mRNA expression of M1 polarization markers and increased M2 markers in RAW 264.7 macrophages cultured in media collected from LPS + CoCl2-simulated adipocytes (p < 0.05). Further, within LPS + CoCl2-stimulated adipocytes, PT reduced reactive oxygen species accumulation, nuclear factor-κB activation, and apoptotic protein expression (p < 0.05). Overall, apple flavonols attenuate critical aspects of the obese AT phenotype.

scholarly journals Piperine Alleviates Doxorubicin-Induced Cardiotoxicity via Activating PPAR-γ in Mice

PPAR Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jie Yan ◽  
Si-Chi Xu ◽  
Chun-Yan Kong ◽  
Xiao-Yang Zhou ◽  
Zhou-Yan Bian ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiac Injury ◽  
Inflammatory Factors ◽  
Peroxisome Proliferator ◽  
Protective Effects ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Myocardial Oxidative Stress

Background. Oxidative stress, inflammation and cardiac apoptosis were closely involved in doxorubicin (DOX)-induced cardiac injury. Piperine has been reported to suppress inflammatory response and pyroptosis in macrophages. However, whether piperine could protect the mice against DOX-related cardiac injury remain unclear. This study aimed to investigate whether piperine inhibited DOX-related cardiac injury in mice. Methods. To induce DOX-related acute cardiac injury, mice in DOX group were intraperitoneally injected with a single dose of DOX (15 mg/kg). To investigate the protective effects of piperine, mice were orally treated for 3 weeks with piperine (50 mg/kg, 18:00 every day) beginning two weeks before DOX injection. Results. Piperine treatment significantly alleviated DOX-induced cardiac injury, and improved cardiac function. Piperine also reduced myocardial oxidative stress, inflammation and apoptosis in mice with DOX injection. Piperine also improved cell viability, and reduced oxidative damage and inflammatory factors in cardiomyocytes. We also found that piperine activated peroxisome proliferator-activated receptor-γ (PPAR-γ), and the protective effects of piperine were abolished by the treatment of the PPAR-γ antagonist in vivo and in vitro. Conclusions. Piperine could suppress DOX-related cardiac injury via activation of PPAR-γ in mice.

The role of Toll-like receptor proteins (TLR) 2 and 4 in mediating inflammation in proximal tubules

2013 ◽  
Vol 305 (2) ◽  
pp. F143-F154 ◽  
Author(s):  
Harshini Mudaliar ◽  
Carol Pollock ◽  
Muralikrishna Gangadharan Komala ◽  
Steven Chadban ◽  
Huiling Wu ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Inflammatory Responses ◽  
Proximal Tubules ◽  
Peroxisome Proliferator ◽  
Tlr2 Expression ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Diagnostic Threshold

Inflammatory responses are central to the pathogenesis of diabetic nephropathy. Toll-like receptors (TLRs) are ligand-activated membrane-bound receptors which induce inflammatory responses predominantly through the activation of NF-κB. TLR2 and 4 are present in proximal tubular cells and are activated by endogenous ligands upregulated in diabetic nephropathy, including high-mobility group box-1 (HMGB1) and fibronectin. Human proximal tubules were exposed to 5 mM (control), 11.2 mM (approximating the clinical diagnostic threshold for diabetes mellitus), and 30 mM (high) glucose for 72 h or 7 days. Cells were harvested for protein, mRNA, and nuclear extract to assess for TLR2, 4, and inflammatory markers. Glucose (11.2 mM) maximally increased TLR2 and 4 expression, HMGB1 release, and NF-κB activation with increased expression of cytokines. However, only TLR2 expression and subsequent NF-κB binding were sustained at 7 days. Recombinant HMGB1 induced NF-κB activation, which was prevented by both TLR2 silencing [small interfering (si)RNA] and TLR4 inhibition. Peroxisome proliferator-activated receptor-γ (PPAR-γ) transcription was reduced by exposure to 11.2 mM glucose with an increase observed at 30 mM glucose at 24 h. This may reflect a compensatory increase in PPAR-γ induced by exposure to 30 mM glucose, limiting the inflammatory response. Therefore, short-term moderate increases in glucose in vitro increase HMGB1, which mediates NF-κB activation through both TLR2 and 4. Furthermore, in vivo, streptozotocin-induced diabetic mice exhibited an increase in tubular TLR2 and HMGB1 expression. These results collectively suggest that TLR2 is likely to be the predominant long-term mediator of NF-κB activation in transducing inflammation in diabetic nephropathy.

scholarly journals Anti-Diabetic Countermeasures Against Tobacco Smoke-Dependent Cerebrovascular Toxicity: Use and Effect of Rosiglitazone

2019 ◽  
Vol 20 (17) ◽  
pp. 4225 ◽  
Author(s):  
Farzane Sivandzade ◽  
Luca Cucullo
Keyword(s):  
Cerebrovascular Disorders ◽  
Protective Role ◽  
Peroxisome Proliferator ◽  
Related Factor ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cerebrovascular Dysfunction ◽  
Public Health Hazards

Tobacco smoking (TS) is one of the most addictive habit sand a main public health hazards, impacting the vascular endothelium through oxidative stress (OS) stimuli, exposure to nicotine, and smoking-induced inflammation in a dose-dependent manner. Increasing evidence also suggested that TS increases glucose intolerance and the risk factor of developing type-2 diabetes mellitus (2DM), which, along with TS, is connected to blood–brain barrier (BBB) injuries, and heightens the risk of cerebrovascular disorders. Although the exact mechanism of rosiglitazone (RSG) is unknown, our previous in vitro work showed how RSG, an oral anti-diabetic drug belonging to the family of thiazolidinedione class, can protect BBB integrity through enhancement of nuclear factor erythroid 2-related factor (Nrf2) activity. Herein, we have validated the protective role of rosiglitazone against TS-induced BBB impairment in vivo. Our results revealed that RSG as a peroxisome proliferator-activated receptor gamma (PPARγ), activates counteractive mechanisms primarily associated with the upregulation of Nrf2 and PPARγ pathways which reduce TS-dependent toxicity at the cerebrovascular level. In line with these findings, our results show that RSG reduces inflammation and protects BBB integrity. In conclusion, RSG offers a novel and promising therapeutic application to reduce TS-induced cerebrovascular dysfunction through activation of the PPARγ-dependent and/or PPARγ-independent Nrf2 pathway.

Physiological Functions of Peroxisome Proliferator-Activated Receptor β

2014 ◽  
Vol 94 (3) ◽  
pp. 795-858 ◽  
Author(s):  
Jaap G. Neels ◽  
Paul A. Grimaldi
Keyword(s):  
Therapeutic Option ◽  
Cell Types ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
In Vivo Models ◽  
Physiological Functions ◽  
Regulatory Pathways ◽  
Inflammatory Conditions

The peroxisome proliferator-activated receptors, PPARα, PPARβ, and PPARγ, are a family of transcription factors activated by a diversity of molecules including fatty acids and fatty acid metabolites. PPARs regulate the transcription of a large variety of genes implicated in metabolism, inflammation, proliferation, and differentiation in different cell types. These transcriptional regulations involve both direct transactivation and interaction with other transcriptional regulatory pathways. The functions of PPARα and PPARγ have been extensively documented mainly because these isoforms are activated by molecules clinically used as hypolipidemic and antidiabetic compounds. The physiological functions of PPARβ remained for a while less investigated, but the finding that specific synthetic agonists exert beneficial actions in obese subjects uplifted the studies aimed to elucidate the roles of this PPAR isoform. Intensive work based on pharmacological and genetic approaches and on the use of both in vitro and in vivo models has considerably improved our knowledge on the physiological roles of PPARβ in various cell types. This review will summarize the accumulated evidence for the implication of PPARβ in the regulation of development, metabolism, and inflammation in several tissues, including skeletal muscle, heart, skin, and intestine. Some of these findings indicate that pharmacological activation of PPARβ could be envisioned as a therapeutic option for the correction of metabolic disorders and a variety of inflammatory conditions. However, other experimental data suggesting that activation of PPARβ could result in serious adverse effects, such as carcinogenesis and psoriasis, raise concerns about the clinical use of potent PPARβ agonists.

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